Yes. During the pandemic, the time people have to elect COBRA (normally just 60 days) has been extended by up to one year. So you still have time to elect COBRA. And because your qualifying event was loss of employment, you are also eligible for the COBRA subsidy.
Normally when people elect COBRA, coverage and premiums take effect retroactively back to your qualifying event. However, a special rule applies to subsidy-eligible individuals who lost employment before April 1 and who haven’t yet elected COBRA. For these individuals only, once you elect COBRA, coverage and premiums will take effect starting April 1.